The tropical disturbance (Invest 93L) that crossed over Florida on Wednesday, bringing welcome rains of 1 - 3 inches, is now a naked swirl of low clouds over the central Gulf of Mexico. The disturbance is embedded in a large area of dry air associated with an upper level low pressure system, and this dry air is discouraging development. 93L is also moving into a region of moderate wind shear of 10 - 20 knots, and NHC is giving 93L a 0% chance of developing into a tropical depression before the storm makes landfall in Mexico south of Brownsville on Saturday. There are a few heavy thunderstorms trying to fire up near the center of 93L's fairly well-formed circulation, but I don't think this storm is going to bring more than 1 - 2 inches of rain to the coast on Saturday.

Central Caribbean disturbance 94LDisorganized heavy thunderstorm activity continues in the region between Central America and Jamaica. Wind shear has fallen to the moderate range, 10 - 20 knots, and is predicted to continue to fall over the next two days. This should allow the disturbance, dubbed Invest 94L by NHC on Friday afternoon, to increase in organization, though it will take many days for it to approach tropical depression status, since it is so large and poorly organized. The last two runs of the NOGAPS model have developed the disturbance into a tropical depression or storm by early next week, with the system moving northwards into Jamaica, the Cayman Islands, and eastern Cuba. The other major models do not show the disturbance developing during the coming week. NHC is giving the disturbance a 10% of developing into a tropical depression by Sunday. A surge of moisture accompanying a tropical wave may aid development when the wave arrives in the Western Caribbean on Sunday. Water temperatures in the Central Caribbean are about 1°C above average, 29°C, which is plenty warm enough to support development of a tropical storm. Residents of Jamaica, eastern Cuba, the Cayman Islands, Haiti, and the Dominican Republic should anticipate the possibility that heavy rains of 2 - 4 inches may affect them today through Sunday.

Five EF-5 tornadoes confirmed in 2011The National Weather Service in Oklahoma City announced Wednesday that the violent tornado that hit Binger, El Reno, Peidmont, and Guthrie, Oklahoma on May 24, killing nine people, was an EF-5 with winds greater than 210 mph. The rating was given based on measurements made by a University of Oklahoma portable "Doppler on wheels" radar. The long track, large wedge tornado caused extensive damage, with well built houses cleanly swept from their foundation and trees debarked. This tornado brings the total number of EF-5 tornadoes this year to five, tying 2011 with 1953 for 2nd place for greatest number of these top-end tornadoes in one year. Only 1974 (six) had more. The EF-5 tornadoes of 2011:

- The April 25 - 28 tornado outbreak, with 330 tornadoes, was the largest tornado outbreak of three days or less duration on record. The previous record was 148 tornadoes, set during the April 3 - 4, 1974 Super Outbreak.

- For April 27, 186 tornadoes have been confirmed. This is the largest 1-day tornado total on record, beating the 148 recorded in 24 hours on April 3 - 4, 1974.

- The April 14 - 16 tornado outbreak, with 162 confirmed tornadoes, ranks as the fourth largest tornado outbreak of three days or less duration on record.

- April confirmed tornado total was 683, making it the busiest tornado month on record. The previous record was 542 tornadoes, set in May 2003. The previous April record was 267 tornadoes, which occurred in April 1974. The 30-year average for April tornadoes is 135.

- If the three deaths in Massachusetts from Wednesday's tornadoes are confirmed, this year's tornado death toll will be 522, beating 1953 as the deadliest tornado year since modern tornado records began. That year, 519 people died, and three heavily populated cities received direct hits by violent tornadoes. Waco, Texas (114 killed), Flint, Michigan (115 killed), and Worcester, Massachusetts (90 killed) all were hit by violent F-4 or F-5 tornadoes. A similar bad tornado year occurred in 1936, when violent tornadoes hit Tupelo Mississippi (216 killed), and Gainesville, Georgia (203 killed.) During that time period, the tornado death rate per million people was 60 - 70 times as great as in the year 2000 (Figure 4), implying that this year's tornadoes would have killed many thousands of people had we not had our modern tornado modern warning system.

- The May 22, 2011 Joplin, Missouri tornado killed 138 people and injured 1150, making it the deadliest U.S. tornado since 1947, and 8th deadliest in history. The $1 - $3 billion estimate of insured damage makes it the most expensive tornado in history.

- Damage from the April 25 - 28 super tornado outbreak was estimated at $3.5 - $6 billion, making it the most expensive tornado outbreak of all-time.

- The tornado that hit Springfield, Massachusetts on June 1 was at least an EF-3 with 136 - 165 mph winds. It was only the 9th EF-3 or stronger tornado to hit Massachusetts since 1950, and the third deadliest, with three deaths.

- The year 2011 now ranks in 3rd place behind 1974 and 1965 for highest number of strong to violent EF-3, EF-4, and EF-5 tornadoes (Figure 3.)

Figure 3. Number of strong to violent EF-3, EF-4 and EF-5 tornadoes from 1950 to 2011. The year 2011 now ranks in 3rd place behind 1974 and 1965. There is not a decades-long increasing trend in the numbers of these most dangerous of tornadoes. Image credit: NOAA/National Climatic Data Center (updated using stats for 2008 - 2011 from Wikipedia.)

Figure 4. Death rate per million people per year in U.S., 1875-2000. Thin line with dots is raw rate, curved thick line is death rate, filtered by 3-point median and 5-point running mean filter, and straight solid lines are least squares fit to filtered death rate for 1875-1925 and 1925-2000. Dashed lines are estimates of 10th and 90th percentile death rates from 1925-2000. The death rate fell from 8 per million to .12 per million between 1940 and 2000. Image credit: A Brief History of Deaths from Tornadoes in the United States, Harold Brooks and Charles Doswell III.

Joplin tornado the 7th U.S. billion-dollar weather disaster of 2011The Joplin tornado is the 7th U.S. weather disaster of 2011 costing more than a billion dollars. With a major flooding disaster coming on the Missouri River, and hurricane season still to come, 2011 has an excellent chance of beating 2008's record of nine billion-dollar weather disasters. The billion dollar weather disasters of 2011 so far:

The next U.S. billion-dollar weather disaster: a Missouri River flood?A great 100-year flood has arrived along the Missouri River and its tributaries from Montana to Nebraska. Record spring rains, combined with snow melt from record or near-record winter and spring snows, brought the Missouri River at Williston, North Dakota to 27.9' yesterday, just an inch short of the highest crest on record (28.0' on 4/01/1912.) Tributaries to the Missouri, such as the Souris River in North Dakota and the North Platte River in Nebraska, are already flooding at all-time record heights. With warm summer temperatures and additional rainfall expected over much of the area during the coming week, snow melt and rain runoff will swell area rivers even further, creating a damaging 100-year flood. Wunderground weather historian Christopher C. Burt has the details in his latest post, and I will be writing more on this latest epic flood next week.

I'll have a new post on Monday, or earlier if the Caribbean disturbance shows significant development.

I still think there will be a considerable burst of convection to the immediate SE of Jamaica. The high cirrus clouds at the periphery of the system is showing good outflow. Should be an interesting watch the next few hours. I got to go, but let me know what happens.

94L has two things going for it, that it didnt have yesterday. The mid-level southwesterly shear is relaxing and the mid-levels are moistening up. I thought 94L was toast 24 hours ago! Looks like I was wrong. Its in better shape than 24 hours ago, but its still going to take at least until mid week to reach TD status. IMO

Point is, this doesn't have the type of organization that you'd use a flight on.

I gotta disagree... while 94L is locked in place and the models don't do much with it the rate it stacking, the amount of energy it is all set to draw on from the Ocean and SA monsoon, the favorable upper level conditions and that fact recon flight are also research flights makes it worthwhile.Also the pressure is dropping...I'm not saying it will, but there is potential for 94L to blow up and take over. Maybe a 2% chance. At this point good pressure data is KEY! and you can't get that without a flight.

RegardlessAt a minimum it is going to bring TS conditions to the West/Central Caribe even if it never officially forms into a TS and 5 days is a long time to be dumped on for Jamaica and the Caymans.

Always disappointing to see a cancelled recon but its their call. Anyways, 94L still holding strong with convection on its Eastern front but is slacking on the western side of the circulation which is still broad and does not appear to be down to the surface. Though, development is looking more likely today than yesterday.

3. REMARK: LOW-LEVEL INVEST MISSION FOR 05/1800Z AND FIXMISSION FOR 06/0600Z CANCELED BY NHC AT 05/1100Z.CANCELED BY NHC...CANCELED BY NHC....CANCELED BY NHC.....(continues repeating for 10 minutes)*drools*Man, we should get more data, if it wasn't for the cancellation.